<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      let dictionary = Object.create(null);
      dictionary.apple = "Apple";
      dictionary.__proto__ = "test";
      // dictionary.toString = function () {
      //   return this.apple + "," + this.__proto__;
      // };
      Object.defineProperty(dictionary, "toString", {
        value: function () {
          return this.apple + "," + this.__proto__;
        },
      });
      for (let key in dictionary) {
        console.log(key);
      }
      console.log(dictionary + "");
    </script>
  </body>
</html>
